Abrading apparatus



Oct. 3, .1944. w. L. KEEFER ABRADING APPARATUS Filed June 12, 1942 2 Sheets-Sheet l Oct. 3, 1944.

w. 1. KEEFER ABRADING APPARATUS 2 Sheets-Sheet 2 Fild June 12, 1942 lzzziarflfiefer M Maw-411 6 f %M@W Patented Oct. 3, 1944 ABRADING APPARATUS Walter L. Keefer, Hagerstown, Md., assignor to Pangborn Corporation, Hagerstown, Md., a corporation of Maryland Application June 12, 1942, Serial N0. 445,746

23 Claims.

This invention relates to abrading apparatus, and more particularly pertains to apparatus for mechanically throwing abrasive at.an abrading velocity and in a concentrated stream against articles to be blasted or abraded.

The invention is primarily concerned with a transfer mechanism for such apparatus which causes the abrasive to be thrown in a concentrated stream. The transfer mechanisms which have heretofore been devised for causing a concentration of the abrasive stream have had certain disadvantages in that the parts have been subjected to considerable wear or have been expensive to manufacture or difiicult to replace.

With the feed control means of the present invention a minimum amount of wear results and moreover the parts which become Worn may be cheaply fabricated and be readily replaced.

In the accompanying drawings:

Fig. 1 is a front elevation of a preferred embodiment of the invention as the apparatus would appear in section on the line I-I of Fig. 2.

Fig. 2 is a section on the line 2-2 of Fig. 1.

Fig. 3 is a diagrammatic view showing the interior surface of the feed control member developed, several different positionings .of an impeller rib or vane being shown in its proper relation with respect to this surface.

Fig. 4 is a perspective of the impeller member.

Fig. 5 is a perspective of the feed control member.

Fig. 6 is a transverse sectional view through a modified form of a feed control member and its associated impeller member.

Fig. 7 is a perspective view of a modified impeller member which may be substituted for that shown in Fig. 4.

The abrasive to be handled by the apparatus is fed thereto by a feed spout Ill. Abrasive may be supplied to this feed spout II) from any suitable elevated source such as a supply hopper (not shown). The lower end of the feed spout I communicates with a circular opening in the front end wall II of a tubular or hollow feed control member shown generally at I2. The feed spout is retained within the central opening of the front end wall II by means of a plurality of clamps, one of which is shown at I3.

The feed control member I2 is formed with a peripheral flange I 4 which seats within a circular opening in the front wall I of the machine housing. To retain the feed control member I2 within this opening in the housing wall I5 a plurality of clamps are provided, and one of these clamps is shown at I6 in Fig. 2. By loosening the clamps I3 and IS the feed control member I2 may be rotated within the opening in the housing wall I5 while the feed pipe l0 and the housing wall I5 remain stationary.

A cylindrical wall ll of the feed control'member I2 extends beyond the flange I4 and terminates in an edge which defines a helix which is 360 degrees in extent. This helical edge is provided with an inturned lip I8 which extends throughout the circumferential extent of the helical edge. A free edge I9 is thus formed between the extremities of the helical edge, this edge I9 extending in a direction parallel to the axis of the cylindrical wall H. In the apparatus illustrated this edge I9 is approximately half as long as the feed control member I2.

The internal surface 20 of the cylindrical wall I'I therefore extends from the end wall II of the control member I2 to the helical edge at the other end having the inturned lip I8. As is best evident from Fig. 2, abrasive is fed into the control member I2 at one end thereof or adjacent the end wall II and escapes from the interior of the control member I2 at the other end thereof over edge I9 as a discharge edge.

The abrasive delivered from the lower end of the feed pipe I0 is caused to fall upon the surface 2|] adjacent the end wall II and away from the inturned lip I8 by the presence of a battle wall 22. This baflle wall 22 is an end wall of a cylindrical protuberance 23 which is a part of the feed control member I2 and projects inwardly from its front wall I I. Through this wall 23 are openings 24 for the escape of abrasive downwardly upon the surface 20. The openings 24 are formed through the cylindrical wall 23 at all portions around the periphery thereof, so that the abrasive will fall downwardly upon the surface 20 through the openings 24 irrespective of the orientation of the feed control member I2. The openings 24 are inclined from a radial plane and slant outwardly in the direction of rotation indicated by the arrow in Fig. l.

The cylindrical protuberance 23 is preferably concentric with the axis of the cylindrical wall II. Also, the cylindrical protuberance is of small diameter compared to the diameter of the control member I2, and as a result an annular space is provided between the periphery of the protuberance 23 and the internal surface 20.

To cause the abrasive tomove from the point near the end wall II at which it is deposited upon the surface 20, to the discharge edge I9, a plurality of rotatably mounted impeller ribs 26 are provided. These ribs 26 extend from a point close to the end wall II to a point beyond the control member and to a radial web 21 of the impeller member 28 of which they are a part. The impeller member 28 also includes a cylindrical wall 29 which extends from the radial web 21 approximately midway toward the extreme free ends of the ribs 26. As appears in Fig. 2 the internal surface of the cylindrical wall 29 is approximately of the same diameter. as the innermost edges of the ribs 26. The exterior surface of the cylindrical wall 29 is not, however, of as large diameter as the outer edges of the ribs 26 with the result that the ribs 26 form projections upon the exterior surface of the cylindrical wall 29 as best appears from Fig. 4.

Du to their support by the cylindrical wall 29, the ribs 26 are circumferentially arranged. Their free ends extend into the annular space between the periphery of protuberance 23 and the internal wall 20.

The side faces of the ribs 26, as shown, are parallel to each other but the outer edge 39 and the inner edge 3| of these ribs slope as shown in Fig. 1. The outer edge 38 and the inner edge 3! converge toward each other in a direction away from the direction of their rotation; Thus, the face of each rib 26 which bears upon the abrasive is broader than the rearward face of the rib.

The end face 32 of the cylindrical wall 29 is of conical formation flaring outwardly away from the cylindrical wall 29 as shown in dotted lines in Fig. 2. This surface 32 tends to cause abrasiv which issues from the openings 24 to be deposited toward the end wall H upon the surface 28. It will thus be apparent that the bafiie wall 22 and the conical surface 32 cooperate to prevent abrasive supplied from the feed pipe lil from immediately passing to the helical end of the control member [2. The movement of the abrasive deposited upon the surface 20 to and over the discharge edge [9 is therefore under the control of the ribs 26.

The impeller member 28 is secured by means of a bolt 34 to a circular boss 35 on the front face of a flange 36. The flange 36 is carried by a shaft 3'? which is supported for rotation in any suitable bearings (not shown) and rotated by a suitable prime mover.

Attached to the flange 36 by any suitable means is a runner head 38. The runner head 38 is centered with respect to the axis of the shaft 31 by having a central opening which seats upon the periphery of the boss 35. The base of the impeller member 28 is also centered by entering within this same opening at the center of the runner head 38. For this reason the base of the impeller member 28 and the boss 35 are of the same diameter.

Attached to the front face of the runner head 38 are a plurality of propelling blades 39. One suitable manner of attachment of these blades 39 to the runner head 38 is fully disclosed in Keefer application, ser. No. 324,860, filed in March 19, 1940, which matured as Patent 2,320,364, June 1, 1943, but it may here be pointed out that the front face of the runner head is provided with radially extending dove-tailed grooves which receive a dove-tailed formation at the supported edge of the blades 39. A pin 40 enters a recess in the runner head 38 and by passing through a notch in the dove-tailed formation of the blade serves to retain the blade against endwise movement.

The discharge edge l9 should be so located that the abrasive discharged thereover will be delivered upon the blades 39 as the blades rotate past the edge NJ. The discharge edge l9 measured parallel to the axis of rotation preferably is not as long as the length of the inner edge of the blades 39, and the edge l9 therefore should be centered with respect to the inner edge of the blades 39.

In the operation of the apparatus the control member l2 remains stationary in its set nosition and the impeller 28 and throwing blades 39 rotat with the runner head 38. Abrasive delivered by the feed pipe [0 is deposited, as has been stated, upon the surface 20 adjacent the end wall H and away from th inturned lip l8 at the helical edge of the feed control member l2. The abrasive so deposited is acted upon by the impeller ribs 26 and is moved around the internal surface 26 by the vanes or ribs 26. In this movement of the abrasive under the action of the impeller ribs 26, the abrasive spreads out in an axial direction and inasmuch as it cannot spread toward the wall l l due to the presence of the end wall H the abrasive spreads out in the opposite axial'direction toward the inturned lip This spreading action of the abrasive in an axial direction is shown diagrammatically in Fig. 3, in which an impeller rib at the position 26a is shown with a pile of abrasive 41a in front of it. By the time this same impeller rib has advanced to the position shown at 26b in Fig. 3 the abrasive in front of the rib or vane will have spread out in an axial direction toward the inturned lip l8 as indicated at 4lb. As this same rib advances further toward the discharge edge H] the abrasive will continue to spread out toward the inturned lip l8 so that by the time the rib reaches the edge l9 abrasive will be advanced by the rib or vane substantially across the entire width of the discharge edge l9. The abrasive will therefore be projected in the direction indicated by the arrows 42 in Fig. 3 beyond the limits of the feed control member l2. This discharged stream of abrasive 42 is also indicated in Fig. 1.

The abrasive which is moved circumferentially by the impeller rib 26 at the part thereof which does not register with the discharge edge i9 is retained within the feed control member and is carried around again within the control member, additional abrasive being added thereto from the feed pipe I0. This abrasive now in front of the impeller rib 26 will spread out in an axial direction toward the inturned lip I8 for ultimate discharge over the edge IS in the manner which has been described. Due to the large number of the impeller ribs 26 which are provided, the stream of abrasive 42 will be a substantially constant one. i

This stream of abrasive 42 will be projected in a direction which is substantially tangential to the internal surface 26 at the discharge edge I9. This stream of abrasive will therefore pass into the orbit of movement of the propelling blades 3 9 to be successsively picked up by them. Due to the action of centrifugal force the abrasive will move outwardly along the surface of the blades and finally will be discharged from the outermost ends of the propeller blades. In this. outward movement of abrasive along the blades 39, it will gain velocity not only due to the more rapid linear movement of successively outer portions of the blades, but due to the increased velocity of the abrasive along the face of the blade due to the action of centrifugal force. The abrasive, as it leaves the blades 39, will have an abrading velocity and therefore will clean or otherwise act upon the surface of articles exposed to the action of the abrasive stream.

Due to the fact that the stream of abrasive 42 passes into the orbit of movement of the blades 39 at only one point or zone in their movement, the abrasive leaving the outer ends of the blades 39 will be concentrated in a stream which extends over only a small portion of the entire circumference of the wheel. In this manner substantially all of the abrasive fed to the wheel is controlled and discharged in a predetermined direction and this direction of discharge may be controlled by suitably orienting the feed control member l2 about its axis.

The transfer mechanism, which comprises the control member I2 and impeller 28, is subjected to little wear as all the abrasive advanced by the ribs and in line with the discharge edge l9 must leave the control member and cannot be churned around inside of the control member. This is because of the helical edge end formation and the discharge edge [9 provides a control member having no peripheral wall forwardly of the discharge point or zone with respect to the direction of rotation, in contrast to a construction in which an opening of limited arouate extent is formed in the periphery of a feed control container.

As the abrasive leaves the control member l2 in an unrestricted manner, and is not churned about within the control member, the abrasive is not disintegrated to the extent it is in a container having a limited opening in its periphery.

Replacement of the parts of the transfer mechanism is readily performed. To remove the feed control member 12 th feed pipe in is first removed by removing the clamps l3. Then the clamps l6 are removed and the control member 12 is simply withdrawn in an axial direction. If the impeller 28 is also to be removed, this is done by unscrewing the bolt 34 after the control member I2 is removed.

In the modification appearing in Fig. 6, the circumferential wall 45 of the feed control member is of frusto-conical'shape, instead of cylindrical. Its larger end is disposed toward the runner head of the apparatus and it is the edge at this end which is of helical formation. The ribs 46 define a frustum of a cone and. they thereby conform generally to the interior of the wall 45. The support 41 for the ribs 46 is likewise of frusto-conical shape, instead of being cylindrical.

This formation of Fig. 6 has the advantage of assisting the axial movement of the abrasive from its point of feed within the control cage to the discharge edge. That is, the spreading action of the abrasive is assisted by the centrifugal force developed by the abrasive in its circular movement around the interior of Wall 45 under the driving action of the ribs 46.

The modified impeller of Fig. 7 also will serve to assist the axial movement of the abrasive within the feed control member. This impeller may be substituted for impeller 28 directly in control member I2. The impelling ribs 48 of this modified impeller define a cylinder, but the ribs are slightly inclined with respect to radial planes through the axis of that cylinder. This inclination is such as to cause the portion of a rib 48 registering with the discharge edge of the control member to be rearwardly with respect to the di rection of rotation of the impeller, from the point of feed of abrasive within the control member.

Due to this inclination of the ribs 48' there will be a slight push upon the abrasive tending to positively advance it lengthwise of the rib and toward the discharge edge. It will be apparent that the ribs 46 in Fig. 6 may have this rearward inclination in addition to their frusto-conical formation shown, to assist the axial movement of the abrasive.

I claim:

1. An abrasive throwing apparatus comprising an abrasive feed control member of generally circular cross-section, one end of said member having an edge which is inclined to a plane perpendicular to the axis of the member, forming a discharge edge which is generally parallel to the axis of the member, means for feeding abrasive within said member at a point further inwardly from said end than said inclined edge, means supported for movement within the interior of said member to move the abrasive circumferentially around the interior thereof and toward said discharge edge whereby the abrasive advances axially toward said end of the member and is delivered from said discharge edge, and blades mounted for rotatable movement about said member for receiving the abrasive delivered from said discharge edge.

2. An abrasive throwing apparatus comprising an abrasive feed control member of generally circular cross-section, said member having at one end thereof an edge substantially parallel to the axis of the member and another edge which is inclined to and which opposes said paralle1 edge whereby the Wall of the control member is absent directly in front of said parallel edge, means for feeding abrasive within said member at a point further inwardly from said end than said inclined edge, means supported for movement within the interior of said member to move the abrasive circumferentially around the interior thereof and toward said discharge edge whereby the abrasive advances axially toward said end of the member and is delivered over said parallel edge, and blades mounted for rotatable movement about said member for receiving the abrasive delivered over said parallel edge. I

3. An abrasive throwing apparatus comprising an abrasive feedcontrol member of generally circular cross-section, and having at one end thereof-an edge which is substantially parallel to the axis of said member and an edge which extends from one extremity of said parallel edge around the member and to the other extremity of said parallel edge, whereby said parallel edge is unobstructed for the escape of abrasive thereover from the interior of the member, means for feed. ing abrasive within said member at a point inwardly from said end, means supported for movement within the interior of said member to move the abrasive circumferentially around the interior thereof whereby the abrasive advances axially toward said end of the member and is delivered from said parallel edge, and blades mounted for rotatable movement about said member for receiving the abrasive from said parallel edge.

4. An abrasive throwing apparatus comprising an abrasive feed control member of generally circular cross-section, one end of said member having an edge of helical formation extending entirely around the member and forming a discharge edge joining the extremities of said helical edge, said discharge edge being substantially parallel to the axis of said member, means for depositin abrasive within said member at a point inwardly from said end thereof, means supported for movement within the interior of said member to move the abrasive circumferentially around the interior thereof whereby the abrasive advances axiall toward said end of the member and is delivered from said discharge edge, and blades mounted for rotatable movement about said member for receiving the abrasive delivered from said discharge edge.

5. An abrasive throwing apparatus comprising an abrasive feed control member of generally circular cross-section, one end of said member having an edge of helical formation extending entirely around the member and forming a discharge edge joining the extremities of said helical edge, said discharge edge being substantially parallel to the axis of said member, an inturned lip :along said helical edge, means for depositing abrasive within said member at a position axially spaced from said helical edge, means supported for movement within the interior of said member to move the abrasive circumferentially around the interior thereof whereby the abrasive advances axially toward said end of the member and is delivered from said discharge edge, and blades mounted for rotatable movement about said member for receiving the abrasive delivered from said discharge edge.

6. An abrasive throwing apparatus comprising an abrasive feed control member of generally circular cross-section, one end of said member having an edge of helical formation extending entirely around the member and forming a discharge edge joining the extremities of said helical edge, said discharge edge being substantially parallel to the axis of said member, said discharge edge being approximately half the length of sa d member, means for depositing abrasive within said member at a point inwardly from said end thereof, means supported for movement within the interior of said member to move the abrasive circumferentially around the interior thereof whereby the abrasive advances axially toward said end of the member and is delivered from said discharge edge, and blades mounted for rotatable movement about said member for receiving the abrasive delivered from said discharge edge.

7. An abrasive throwing apparatus comprising 1 an abrasive feed control member of generally circular cross-section, one end of said member including an edge which is inclined to a plane perpendicular-to the axis of the member, forming a discharge edge which is generally parallel to the axis of the member, means for feeding abrasive within said member at a point inwardly from said end thereof, a bafile within said control member between said end of the member and said feed means to insure deposit of the abrasive inwardly away from said end of the member, means supported for movement within the interior of said member to move the abrasive circumferentially around the interior thereof whereby the abrasive advances axially toward said end of the member and is delivered from said discharge edge, and blades mounted for rotatable movement about said member for receiving the abrasive delivered from said discharge edge.

8. An abrasive throwing apparatus comprising an abrasive feed control member of generally circular cross-section, one end of said member including an edge which'is inclined to a plane perpendicular to the axis of the member, forming a discharge edge which is generally parallel to the axis of the member, a hollow protuberance extending axially into said control member from the other end of the member and having a perforated side wall and an imperforate inner end, means feeding abrasive within said protuberance and from which the abrasive is deposited upon the interior of said member at a point inwardly from said discharge edge, means supported for movement within the interior of said member to move the abrasive circumferentially around the interior thereof whereby the abrasive spreads axially toward the discharge edge and is projected thereover, and blades mounted for rotatable movement about said member for receiving the abrasive from said discharge edge.

9. An abrasive throwing apparatus comprising an abrasive feed control member of generally circular cross-section, one end of said member including an edge which is inclined to a plane perpendicular to the axis of the member, forming a discharge edge which is generally parallel to the axis of the member, a hollow protuberance extending axially into said control member from the other end of the member and having a perforated side wall and an imperforate inner end, means feeding abrasive within said protuberance and from which the abrasive is deposited upon the interior of said member at a point inwardly from said discharge edge, means supported for movement within the interior of said member to advance the abrasive circumferentially around the interior thereof whereby the abrasive spreads axially toward the discharge edge and is projected thereover, the perforations in said protuberance inclining outwardly in the direction of movement of said abrasive advancing means, and blades mounted for rotatable movement about said member for receiving the abrasive from said discharge edge.

10. A transfer mechanism for an abrasive throwing apparatus comprising an abrasive feed control member of generally circular cross-section, one end of said member including an edge which is inclined to a plane perpendicular to the axis of the member, forming a discharge edge which is generally parallel to the axis of the member, means for feeding abrasive within said member at a point further inwardly from said end than said inclined edge, and a plurality of circumferentially arranged ribs supported for movement around the interior of said member to move the abrasive circumferentially around the interior thereof and toward said discharge edge whereby the abrasive advances axially toward said end of the member and is delivered from said discharge edge.

11. A transfer mechanism for an abrasive throwing apparatus comprising an abrasive feed control member of generally circular cross-section, one end of said'member including an edge which is inclined to a plane perpendicular to the axis of the member, forming a discharge edge which is generally parallel to the axis of the member, means for feeding abrasive within said member at a point further inwardly from said end than said inclined edge, and a plurality of circumferentially arranged ribs supported for movement around the interior of said member to move the abrasiv circumferentially around the interior thereof and toward said discharge edge whereby the abrasive advances axially toward said end of the member and is delivered from said discharge edge, said ribs extending throughout the length of the interior of-said control member.

to a plane perpendicularly to the axis of the 2 member, forming a discharge edge which is generally parallel to the axis of the member, means for feeding abrasive within said member at a point further inwardly from said end than said inclined edge, and means supported for movement within the interior of said member to move the abrasive circumferentially around the interior thereof and toward said discharge edge whereby the abrasive advances axially toward said end of the member and is delivered from said discharge edge.

13. A transfer mechanism for an abrasive throwing apparatus comprising a frusto-conical abrasive feed control member, the end of said member which is of larger diameter including an edge wh ch is inclined to a plane perpendicular to the axis of the member, forming a discharge edge which is generally in a radial plane through the axis of the member, means for feeding abrasive within said member at a point inwardly from said end thereof, and means supported for movement within the interior of said member and generally conforming to the frusto-conica l interior thereof to move the abrasive circumferentially around the interior thereof whereby the abrasive advances axially toward said end of the member and is delivered from said discharge edge.

14. A transfer mechanism for an abrasive throwing apparatus comprising an abrasive feed control member of generally circular cross-section, one end of said member including an edge which is inclined to a plane perpendicular to the axis of the member, forming a discharge edge which is generally parallel to the axis of the member, means for feeding abrasive within said member at a zone inwardly from said end thereof, and a plurality of circumferentially arranged ribs supported for rotary movement around the interior of said member to move the abrasive circumferentially around the interior thereof whereby the abrasive advances axially toward said end of the member and is delivered from said discharge edge, the portions of said ribs registering with said discharge edge lying rearwardly from the portions ofsaid ribs registering with the feeding zone with respect to the direction of rotation of the ribs to assist the movement of the abrasive to said discharge edge.

15. A transfer mechanism for an abrasive throwing apparatus comprising an abrasive feed control member of generally circular cross-section, one end of said member including a discharge edge which is generally parallel to the axis of the member and another edge extending around the member and connecting the extremities of said discharge edge, means for feeding abrasive within said member at a point inwardly from said end thereof, a plurality of ribs arranged circumferentially around the interior of said member, and a support of circular crosssection carrying said ribs upon its periphery, said support being rotatably mounted to move said ribs about the interior of the control member axis of the member, forming a discharge edge which is generally parallel to the axis of the member, means for feeding abrasive into said control member from the other end thereof, a baffle supported by said control member within said member at a point between said discharge edge and said feed means, a rotatably mounted support of circular cross-section extending into said control member from the discharge end thereof and having its end in substantially the same plane as said baflle, said baffle and said end of the support cooperating to insure deposit of abrasive from the feed means within the control member adjacent the feed end thereof, and a plurality of circumferentially arranged ribs carried by said support and extending beyond said end of the support to engage the abrasive deposited within the member and move the abrasive around the interior of the member whereby it advances axially toward said discharge edge for delivery thereover.

17. A control member for the transfer mechanism of an abrasive throwing apparatus comprising a circular wall having at one end thereof an edge which is substantially parallel to the axis of said member and an edge which extends from one extremity of said parallel edge around the member and to the other extremity of said parallel edge, whereby said parallel edge is unobstructed for the escape of abrasive thereover from the interior of the member.

18. A control member for the transfer mechanism of an abrasive throwing apparatus comprising a circular wall having at one end an edge of helical formation extending entirely around the member, forming an abrasive discharge edge joining the extremities of said helical edge, said discharge edge being substantially parallel to the axis of said member, and. a hollow protuberance extending into the interior of the member from the opposite end thereof and having a perforated side wall and an imperforate inner end wall.

19. An impeller member for the transfer mechanism of an abrasive throwing apparatus comprising a support of circular cross-section having circumferentially arranged around its periphery a. plurality of ribs, said ribs extending generally lengthwise of the member but being correspondingly inclined with respect to radial planes through the axis of said support.

20. An impeller for a transfer mechanism of centrifugal abrading apparatus comprising, a rotatable tubular support of generally circular cross section, circumferentially spaced ribs carried by the tubular support projecting substantially axially beyond an end of the tubular support, and the forward faces of said ribs with respect to the direction of rotation of the impeller being of greater radial dimensions than the rear faces thereof.

21. An impeller for a transfer mechanism of centrifugal abrading apparatus comprising, a tubular support of generally circular cross section terminating in an end face corresponding substantially to the radial thickness of the tubular support, circumferentially spaced ribs carried by the tubular support extending axially beyond the end face of the tubular support, and the inner edges of said ribs being substantially aligned with the inner surface of support.

22. A control member for a transfer mechanism of centrifugal abrading apparatus comprising, a generally circular wall terminating at one end in a helical edge, a discharge edge extending said tubular generally axially of the control member joining the extremities of said helical edge, and a lip projecting radially inward from said helical edge and extending throughout the circumferential extent of said helical edge.

23. A control member for a transfer mechanism of centrifugal abrading apparatus comprising, a generally circular wall terminating at one end in an edge of helical shape extending entirely around the circular wall, a discharge edge extending generally axially of the control member and joining the extremities of said helical edge, and a baiiie member within said control member spaced from the helical end thereof.

WALTER L. KEEPER. 

